Abraham's grandson was Esau, who had four letters in his name, and JACOB, who had five letters in his name. Esau and JACOB were the sons of Isaac, the son of Abraham from the Hebrew Bible. Esau was the older twin brother of JACOB and was born first. JACOB tricked Esau out of his birthright and received the blessing of his father Isaac. This event is known as the 'Blessing of JACOB' and is an important part of the Hebrew Bible.